Regulation of phosphate homeostasis by microRNA

A mechanism by which plants regulate phosphate (Pi) homeostasis to adapt to environmental changes in Pi availability was revealed in Dr. Tzyy-Jen Chiou’s lab in ABRC. This mechanism involves the suppression of a ubiquitin-conjugating E2 enzyme (UBC24) by a specific microRNA, miR399. Such regulation mediates Pi uptake from roots, Pi allocation between roots and shoots and Pi recycle among leaves. Moreover, Dr. Chiou’s team further uncovered that a previously identified Pi overaccumulator, pho2, is caused by a single nucleotide mutation resulting in early termination within the UBC24 gene. Chiou, T.-J.* (2007). The Role of MicroRNAs in Sensing Nutrient Stress. Plant, Cell & Environment, 30, pp. 323-332. Aung, K., Lin, S.-I., Wu, C.-C., Huang, Y.-T., Su, C. and Chiou, T.-J.* (2006). pho2, a phosphate overaccumulator, is caused by a nonsense mutation in a miR399 target gene. Plant Physiology, 141, pp. 1000-1011. Chiou, T.-J.*, Aung, K., Lin, S.-I., Wu, C.-C., Chiang, S.-F., and Su, C. (2006). Regulation of phosphate homeostasis by microRNA in Arabidopsis. Plant Cell, 18, pp.412-421. Fujii, H., Chiou, T.-J., Lin, S.-I., Aung, K., and Zhu, J.-K. (2005). A miRNA Involved in Phosphate-Starvation Response in Arabidopsis. Current Biology,,15, pp.2038-2043.